Ceramic Focus Ring for Plasma Etch Equipment
When aluminum alloy is selected as the chamber material of the etcher, it is easy to cause metal particle pollution. Instead, a dense anodic aluminum oxide layer is coated on the aluminum alloy to improve the corrosion resistance of the chamber material through anodic oxidation. It is found in practice that the anodic aluminum oxide layer is prone to spalling. This is mainly because the impurities in the alloy are segregated, and the anodic aluminum oxide layer on the surface is easy to produce microcracks, which makes the service life of anodic aluminum oxide low. Therefore, high-purity alumina ceramics are prepared as chamber materials.
As a plasma etching resistant cavity material, it has the following characteristics.
(1) The production equipment is simple, the degree of automation is high, and the production process cost is low.
(2) Since halogen gas is usually used for high-speed etching of Si wafers, Al is easy to react with halogen f to produce volatile Al-F by-products and pollute the wafers.
(3) The hardness and bending strength decreased obviously with the addition of metal impurities.
(4) At high temperature, the nanocrystals are easy to grow and the thermal conductivity decreases.
(5) In the gradient coating, the delamination effect is aggravated.
(6) It cannot meet the requirements of etching equipment above 300mm.
